One-Pot Friedel−Crafts/Robinson−Gabriel Synthesis of Oxazoles Using Oxazolone Templates
作者:Manasi Keni、Jetze J. Tepe
DOI:10.1021/jo0501590
日期:2005.5.1
We report herein a one-potsynthesis of 2,4,5-trisubstituted oxazoles via a Friedel−Crafts/Robinson−Gabriel synthesisusing a general oxazolone template. Treatment of the oxazolone template with a range of aromatic nucleophiles provided the highly substituted oxazoles in good yields.
A Fluorogenic 1,3-Dipolar Cycloaddition Reaction of 3-Azidocoumarins and Acetylenes
作者:Krishnamoorthy Sivakumar、Fang Xie、Brandon M. Cash、Su Long、Hannah N. Barnhill、Qian Wang
DOI:10.1021/ol047955x
日期:2004.11.1
Copper(I)-catalyzed 1,3-dipolarcycloadditionreaction of nonfluorescent 3-azidocoumarins and terminal alkynes afforded intense fluorescent 1,2,3-triazole products. The mild condition of this reaction allowed us to construct a large library of pure fluorescent coumarin dyes. Since both azide and alkyne are quite inert to biological systems, this reaction has potential in bioconjugation and bioimaging
One-pot cascade reactions of N-acylglycines, acetic anhydride, anhydroussodiumacetate, aromatic aldehydes, and ammonium N-aryldithiocarbamates expeditiously and diastereoselectively yield 5-acylamino-3,6-diarylperhydro-2-thioxo-1,3-thiazin-4-ones (5a–j) in solvent-free conditions under microwave irradiation.
A highly efficient enantio- and diastereoselective catalyzed asymmetrictransferhydrogenation via dynamic kinetic resolution (DKR–ATH) of α,β-dehydro-α-acetamido and α-acetamido benzocyclic ketones to ent-trans-β-amido alcohols is disclosed employing a new ansa-Ru(II) complex of an enantiomericallypure syn-N,N-ligand, i.e. ent-syn-ULTAM-(CH2)3Ph. DFT calculations of the transition state structures
Practical Preparation of <i>Z</i>‐α‐(<i>N</i>‐Acetylamino)‐ and <i>Z</i>‐α‐(<i>N</i>‐Benzoylamino)‐α,β‐unsaturated Acids
作者:Branko S. Jursic、Sarada Sagiraju、Dustin K. Ancalade、Traneil Clark、Edwin D. Stevens
DOI:10.1080/00397910701265895
日期:2007.5.1
An efficient two‐step synthetic procedure for the preparation of numerous variations of N‐protected α,β‐unsaturated α‐amino acids and their corresponding esters from N‐protected glycine and either aliphatic or aromatic aldehydes was developed. The reaction involved cyclization of the N‐protected glycine into oxazolone, condensation with the aldehyde, and ring opening with a base.
摘要 开发了一种有效的两步合成程序,用于从 N-保护的甘氨酸和脂肪族或芳香族醛制备 N-保护的 α,β-不饱和 α-氨基酸及其相应的酯的多种变体。该反应包括将 N 保护的甘氨酸环化为恶唑酮、与醛缩合以及与碱开环。